Tungsten inert gas (TIG) welding is an arc welding process that uses a non-consumable tungsten electrode to produce a metal weld. Generally, a TIG weld area is protected from atmospheric contamination using an inert shielding gas (usually argon or helium) and a joint filling metal. The shielding gases protect the welding area from atmospheric gases such as nitrogen and oxygen which may cause fusion defects, porosity, and weld metal embrittlement. The shielding gas may also transfer heat from the tungsten electrode to the metal, while maintaining a stable arc.
To weld a constant-current welding power supply produces electrical energy that is conducted across a plasma arc composed of a column of highly ionized gas and metal vapors. Negatively charged electrodes generate heat by emitting electrons which travel across the plasma arc causing thermal ionization of the shielding gas and increasing the temperature of the base material. By moving the plasma arc along a desired trajectory a TIG welder can have better control over a weld than when using competing processes such as shielded metal arc welding and gas metal arc welding.
TIG welding has proven itself to be a highly advantageous welding process when used by a skilled welder. A typical TIG welding system includes a welding torch, a cooling system, the constant-current power supply, the inert gas, and a delivery system for the inert gas. TIG welding torches can be designed for either automatic or manual welding operations. Both torches are similar in construction and operation but a manual torch has a handle while an automatic torch normally attaches to a mounting rack. One (1) advantage of the manual TIG torch is that the head angle, the angle between the center-line of the handle and the center-line of the tungsten electrode, may be varied to suit the preferences and skills of the welder.
A TIG welding electrode may include alloys of copper or brass to improve the transmission of current and heat. But the main part of the electrode is the tungsten which is fixed along the center of the TIG torch. The welder initiates a plasma arc by briefly touching a work area that is connected to the constant current source and then moves the plasma arc via the electrode along a desired trajectory to make a weld. Ports around the tungsten electrode provide an avenue for the flow of shielding gas. In practice a plurality of heat-resistant torch gas nozzles of different sizes may be made available to accommodate the required area to be protected by the external gas shield. Hand-operated switches are used to control the welding current. The TIG torch body is almost always made of a heat-resistant and insulating material to protect the operator.
While TIG welding has proven to be extremely useful the inventor has found a process which improves on existing TIG welders. The process can not only improve TIG welding but it can be implemented in a straightforward manner and can be with little to no additional learning required by the welder.